Quaternized Poly(phthalazinone ether sulfone ketone) Membrane Doped with H3PO4 for High-Temperature PEMFC Operation

Abstract

A quaternized poly͑phthalazinone ether sulfone ketone͒ ͑QAPPESK͒ membrane doped with H 3 PO 4 was prepared and characterized. Infrared and 31 P NMR spectra indicated that this membrane may have the same mode of conducting proton as polybenzimidazole ͑PBI͒ membrane doped with H 3 PO 4 . The QAPPESK membrane doped with H 3 PO 4 showed high proton conductivity ͑0.072 S/cm at 150°C͒, and good thermostability measured by thermogravimetric analysis. The peak power density of single cell with QAPPESK/H 3 PO 4 composite membrane and operated at 150°C with dry H 2 /O 2 reached 0.85 W/cm 2 . These results show that QAPPESK/H 3 PO 4 composite membrane is promising for high-temperature proton exchange membrane fuel cell ͑PEMFC͒ applications.During recent years, great efforts have been made to develop novel proton-exchange membranes ͑PEM͒ for high-temperature ͑Ͼ120°C͒ proton-exchange membrane fuel cells ͑PEMFCs͒. PEMFCs operated at higher temperature and low relative humidity possess many advantages, including the avoidance of anode catalyst poisoning caused by CO and fuel cell floodin, the significant improvement of the fuel cell efficiency, reduction in the amount of noble metal catalyst due to fast kinetics at high temperature, and humidification of the reactant gasesis not necessary for high temperature PEMFC systems with dry gases. Therefore, the development of PEM, which has satisfactory proton conductivity at higher temperatures and low relative humidity, is of importance in hightemperature PEMFC research and development. [1][2][3] Acid-base complexation represents an effective approach to develop the proton-conducting membranes. Basic polymers can be doped with an amphoteric acid, which acts both as a donor and an acceptor in proton transfer and therefore allows for the proton migration. A number of basic polymers have been investigated for preparing acid-base electrolytes, such as PBI, 4 PEO, 5 and PVA, 6 polyacrylamide ͑PAAM͒, 7 and polyethylenimine ͑PEI͒. 8 However, few polymers can meet the requirements of PEMFCs operated at high temperature ͑Ͼ120°C͒ and low relative humidity.Poly͑phthalazine ether sulfone ketone͒ ͑PPESK͒ has shown superior mechanical strength, chemical resistance and very high glass transition temperature at the temperature range of 263-305°C. 9 In view of this, in this work, the quaternized poly͑phthalazinone ether sulfone ketone͒ ͑QAPPESK͒ membranes doped with H 3 PO 4 were prepared and characterized for PEMFCs operated at high temperature and low relative humidity. ExperimentalMembrane preparation.-QAPPESK membrane ͑40 m thick͒ was prepared according to literature, 10 and the QAPPESK/H 3 PO 4 composite membrane was obtained by immersing the QAPPESK membrane in an 30% H 3 PO 4 solution for 2 h at 25°C. The amounts of H 3 PO 4 absorbed in the membrane were determined by weighing the membrane before and after immersion. The 100 g QAPPESK can absorb about 400 g H 3 PO 4 ·xH 2 O. The reaction of QAPPESK with H 3 PO 4 is shown in Scheme 1.Membrane-electrode assembly.-The membrane-electrodeassembly ͑...

Blended polybenzimidazole and melamine-co-formaldehyde thermosets

“…In addition, the C-H stretch at 1327 cm -1 for PBI is more intense than the blends. [53][54][55] Dynamic Mechanical Analysis (DMA) has provided additional insight into the physical properties of PBI-PMF and its films. It is difficult to obtain an accurate glass transition (Tg) for PBI using differential scanning calorimetry (DSC).…”

Synthesis and characterization of novel imidazolium-functionalized polyimides for high temperature proton exchange membrane fuel cells

“…The amount of catalyst used is another important parameter for the reaction. For example, DS increased from 0.15 to 1.81 as the amount of SnCl 4 was increased from 1 to 30 mol mol À1 repeating unit when the reaction was carried out for 24 h at 60 C (entry 7, [19][20][21][22]. Gelation was also observed when the amount of catalyst reached 20 and 30 mol mol À1 repeating unit (entry 21,22).…”

“…As the alternative materials for high temperature PEMFCs, a new type of PEMs based on poly(phthalazinone ether sulfone ketone) containing quaternary ammonium groups was rst reported by Li. 22 Quaternary ammonium groups have good bonding ability with PA. Some approaches based on quaternized poly(ether sulfone), [23][24][25] quaternized poly(arylene ether ketone) [26][27][28] and quaternized PBI 29 have been reported.…”

Multilayer Sulfonated Polyhedral Oligosilsesquioxane (S-POSS)-Sulfonated Polyphenylsulfone (S-PPSU) Composite Proton Exchange Membranes

“…Many other H 3 PO 4 composite membrane systems have been studied, for example, the poly(vinylalcohol)/ H 3 PO 4 blend, 26 the poly(ethylenoxide)/poly(methylmethacrylate)/H 3 PO 4 blend, 27 and the poly(acrylamide)/poly(ethylenoxide)/H 3 PO 4 blend. 28 A comparative study was carried out using poly(phthalazinone ether sulfone ketone)/H 3 PO 4 29 where the peak power density of single cell operated at 150 °C with dry H 2 /O 2 reached 0.85 W cm -2 . The disadvantage of long-term stability is believed to be similar to the PBI-H 3 PO 4 system.…”